Japanese Application No. 59-236445 filed in Japan on Nov. 9, 1984 and entitled "Fast Mechanical Shutter", discloses a fast shutter part which rotates continuously. Also included is a photographic shutter part which operates intermittently and an electric circuit which (1) drives the fast shutter part and photographic shutter part by receiving an external image pickup command signal and (2) performs fast mechanical shutter operation.
A slit 5b in the fast shutter part passes by a sensor 8 which then sends an indication signal for closure to a camera shutter 6. A slit 5c in the fast shutter part passes by a sensor 9 which then sends an indication signal for opening the camera shutter 6. A cut part 5a in the fast shutter part only passes through an optical path 10 after the slit 5c passes by the sensor 9 and before the slit 5b passes by the sensor 8 so that light 10 reaches an element 3'. The shutter speed is determined by the rotating speed of the disk and the angle of opening of the cut part 5a viewed from a center shaft of the disk.